A family leaves the Westfield Bondi Junction shopping mall after a stabbing incident in Sydney on Saturday. Reuters

"My wife and I were utterly shocked and horrified to hear of the tragic stabbing incident in Bondi," Charles said in a statement released by Buckingham Palace.

"Our hearts go out to the families and loved ones of those who have been so brutally killed during such a senseless attack.

"While details of these shocking circumstances are still emerging, our thoughts are also with those who were involved in the response, and we give thanks for the bravery of the first responders and emergency services," he added.

King Charles III is the monarch of Australia, which is part of Britain's Commonwealth.

Prince William, wife Kate, 'saddened' by Sydney stabbing

Earlier, his son and heir to the throne Prince William and his wife Catherine said they were "shocked and saddened" by the stabbings.

"Our thoughts are with all those affected, including the loved ones of those lost and the heroic emergency responders who risked their own lives to save others. W & C," the Prince and Princess of Wales said in a post on the social media site X, formerly known as Twitter.

Australian police said multiple people were stabbed by the unidentified assailant, who was tracked down and shot dead by a policewoman.

Agence France-Presse